[png-mng-implement] question about png_do_expand_palette

[John A. <jo...@al...>]

Hello,

I am tring to read in a palette based png image.  Modify the collor of a
couple of the pixels and resave the file either with the same name or a
different name.

I have come along ways by looking through the read and write png
examples.  I have two questions though.  One would it be faster/easier
to simply modify the pallet rgb values and save those to the new file or
should I expand the palette the way I am currently doing, modify the
values this way and repaletize the pixels and resave the values.


I'd actually like to know how to do it both ways.  Modifying the pallete
seems easier, but I would like to know how to expand the palette modify
the rgb values for each pixel and resave them and then shrink the
palette again.

I know how to expand the palette with the png_do_expand_palette method,
but I am not sure about how to repalettize the pixles again.  My current
guess is that it might be the png_do_pack method, but I am not sure.
Any insight/working code anyone can give, would be muchly appreciated.

Thanks,



-- 
John Aldridge <jo...@al...>